Smartphone shelf



FIG. 1 is a perspective view of a smartphone shelf;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a top elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a bottom elevation view thereof; and,

FIG. 6 is a right side elevation view thereof, the left side elevation view being a mirror image thereof.

The broken lines shown in the drawings depict portions of a bottom surface of the smartphone shelf that form no part of the claimed invention. 

CLAIM The ornamental design for a smartphone shelf, as shown and described. 